public class Example {
    String str=new String("good");

    char[] ch = {'a','b','c'};

    public static void main(String args[]){

        Example ex=new Example();

        ex.change(ex.str,ex.ch);

        System.out.print(ex.str+" and ");

        System.out.print(ex.ch);

    }

    public void change(String str,char ch[]){

        str="test ok";

        ch[0]='g';

    }
}